A Critique of East Sussex Speed Limit Policy

We write an open email to Cllr Bennett, Lead Member for Transport and Environment for East Sussex County Council, regarding misrepresentation of DfT guidance in East Sussex briefings to members and the public.

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Dear Councillor Bennett


It has been brought to our attention that East Sussex County Council is circulating two documents that we believe misrepresent DfT guidance on the setting of local speed limits – see the attached ESCC Speed Limit Briefing Note and Member briefing note on the introduction of 20mph schemes in East Sussex.


The effect of this is to stifle the introduction of lower speed limits in East Sussex to protect vulnerable road users and communities in East Sussex. We believe that their continued use could well open the council to litigation on three counts:


  1. Misrepresentation of government guidance;
  2. Where a lower limit may have prevented or mitigated the severity of casualties in the event of crash; and
  3. Where such documents and polices have been adopted without fully considering their impact on people with protected characteristics, as required under the Equality Act 2010.


We suggest that the two documents be withdrawn from circulation as a matter of urgency.  We have critiqued the initial 5 elements of the ESCC Speed limit Briefing note as examples of misrepresentation.  We would be happy to provide further examples and advice about appropriate replacement wording for either or both documents:


ESCC Speed Limit Briefing Note Comment from 20’s Plenty for us
Speed limits should be evidence-led, self-explaining and seek to reinforce a driver’s assessment of what is a safe speed to travel. They should encourage self-compliance.

The quote from the Department for Transport circular 1/2013 on Setting Local Speed Limits is selective and misleading.  See https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/63975/circular-01-2013.pdf

The actual words are

Speed limits should be evidence-led and self-explaining and seek to reinforce people's assessment of what is a safe speed to travel. They should encourage self-compliance.

Note: people, not drivers.  Vulnerable road users’ perception of a safe speed is rather different from that of the driver - 80% of pedestrian and cyclist casualties occur on 30mph roads.

Critically, the briefing note omits the following statement from the circular which shows the DfT’s expectations that traffic authorities will introduce 20mph limits and zones in residential areas and urban settings in order to protect pedestrians and cyclists:

Traffic authorities are asked to keep their speed limits under review with changing circumstances, and to consider the introduction of more 20 mph limits and zones, over time, in urban areas and built-up village streets that are primarily residential, to ensure greater safety for pedestrians and cyclists, using the criteria in Section 6.

On “evidence-led”, ESCC provides no evidence that 30mph is a safe speed limit where cars and vulnerable road users mix.  On the contrary, about half of all casualties in ESCC are on 30mph roads - 994 casualties in 2016, including 183 KSIs – 89 of those killed or seriously injured were pedestrians or cyclists.

Elsewhere in the UK, evidence in favour of 20mph as the right speed for urban settings is growing, with Local Authorities that have introduced 20mph limits reporting lower casualty rates.  E.g. Bristol -14%; Portsmouth and Calderdale -22%, Edinburgh -24%, Newcastle -25% and Burnley -29%.

Around the world, there is no evidence to show that 30mph is a safe speed limit, whereas there is plenty of evidence that 20mph is safer. The latest research, from the OECD’s International Traffic Forum, states:

Where motorised vehicles and vulnerable road users share the same space, such as in residential areas, 30 km/h is the recommended maximum.


The underlying aim should be to achieve a 'safe' distribution of speeds.
The key factors that should be taken into account in any decisions on local speed limits are:
• History of collisions;
• Existing traffic speeds;
• Road geometry and environment;
• Road function;
• Composition of road users.

Another quotation from the DfT Setting Local Speed Limits circular which omits / amends 4 critical phrases:

1)        The aim of speed management policies should be to achieve a safe distribution of speeds consistent with the speed limit that reflects the function of the road and the road environment. This should imply a mean speed appropriate to the prevailing road environment, and all vehicles moving at speeds below or at the posted speed limit, while having regard to the traffic conditions.

This does NOT mean that speed limits should be brought up to the prevailing traffic speeds but, rather, that traffic speeds need to be adapted to the function of the road.  In town and village centres and in residential areas, this means lowering roads speeds sufficiently to allow vulnerable road users to use the roads safely.

2)        Local traffic authorities are responsible for determining speed limits on the local road network.

The traffic authority should not use budget constraints to determine an appropriate speed limit.

3)        The underlying aim should be to achieve a 'safe' distribution of speeds. The key factors that should be taken into account in any decisions on local speed limits are:

·             history of collisions;

·             road geometry and engineering;

·             road function;

·             Composition of road users (including existing and potential levels of vulnerable road users);

·             existing traffic speeds; and

·             road environment

In promoting existing traffic speeds, in relegating “Composition of road users” to the bottom of the list and omitting the emphasised text, ESCC has entirely changed the meaning of the section.

4)        The impact on community and environmental outcomes should also be considered

Although the OECD report referred to notes the desirability of achieving a narrow distribution of speeds around a given mean, this is not an alternative to lowering speeds overall.  The recommendation is to:

Reduce the speed on roads as well as speed differences between vehicles.


Speed has a direct influence on crash occurrence and severity. With higher driving speeds, the number of crashes and the crash severity increase disproportionally.

A study of the types of crashes, their severity, causes and frequency, together with a survey of traffic speeds, should indicate whether an existing speed limit is appropriate for the type of road and mix of use by different groups of road users or whether it needs to be changed.

Again, omitting two critical phrases completely changes the intention of the DfT circular, ignoring the needs of vulnerable road users and local residents:

A study of types of crashes, their severity, causes and frequency, together with a survey of traffic speeds, should indicate whether an existing speed limit is appropriate for the type of road and mix of use by different groups of road users, including the presence or potential presence of vulnerable road users (including people walking, cycling or riding horses, or on motorbikes), or whether it needs to be changed. Local residents may also express their concerns or desire for a lower speed limit and these comments should be considered
The principal aim in determining appropriate speed limits should, therefore, be to provide a consistent message between speed limit and what the road looks like, and for changes in speed limit to be reflective of changes in the road layout and characteristics.

Again a misquote and taken out of the context of previous paragraphs which have been omitted.  The actual quote is:

A principal aim…

In other words, one aim amongst others.  The previous paragraphs describe how speed limits are one component of making roads safer.  There is no intention of absolving a traffic authority from reducing the speed limit on a road where there are or could be vulnerable road users.

20 (including 20 mph zone)

In streets that are primarily residential and in other town or city streets where pedestrian and cyclist movements are high, such as around schools, shops, markets, playgrounds and other areas, where motor vehicle movement is not the primary function.


In other built-up areas with development on both sides of the road.


On higher quality suburban roads or those on the outskirts of urban areas where there is little development or properties set back from the road, with few cyclists, pedestrians or equestrians


On rural roads, dual carriageways or bypasses that have limited frontage development or are only partially built up.

This table once again is “plucked” from the DFT guidance but misses out key elements in favour of lower speed limits. These are shown highlighted below :-

20 (including 20 mph zone)

In streets that are primarily residential and in other town or city streets where pedestrian and cyclist movements are high, such as around schools, shops, markets, playgrounds and other areas, where motor vehicle movement is not the primary function.


In other built-up areas (where motor vehicle movement is deemed more important), with development on both sides of the road


On higher quality suburban roads or those on the outskirts of urban areas where there is little development, with few cyclists, pedestrians or equestrians. On roads with good width and layout, parking and waiting restrictions in operation, and buildings set back from the road. On roads that, wherever possible, cater for the needs of non-motorised users through segregation of road space, and have adequate footways and crossing places.


On dual carriageway ring or radial routes or bypasses that have become partially built up, with little or no roadside development

The implication is that the council is seeking to remove the recommendation that 30mph is only suitable “where motor vehicle movement is deemed more important”.
We note that on 40mph and 50mph recommendations the council briefing makes considerable changes from the DfT guidance.



There are other omissions which alter the whole tone of the DfT guidance . In particular we would reference Para 32 which states :-


“Different road users perceive risks and appropriate speeds differently, and drivers and riders of motor vehicles often do not have the same perception of the hazards of speed as do people on foot, on bicycles or on horseback. Fear of traffic can affect peoples’ quality of life and the needs of vulnerable road users must be fully taken into account in order to further encourage these modes of travel and improve their safety. Speed management strategies should seek to protect local community life.”


This conflicts with the later insistence that “The cost of implementation will therefore need to be prioritised within the available Road Safety Budget.” It is not possible to “fully take into account the needs of vulnerable road users” if the implementation of lower speed limits is prioritised based on an arbitrary cap on expenditure. Other local authorities use various fund to implement the lowering of speed limits. These include section 106 funds, development funds, public health funds, sustainable community grants, etc.


We note that a further document being used within the council is the “Member Briefing on 20mph schemes in East Sussex”. We believe that this also seriously mis-informs members and the public. We note that although the document was created in 2013, it has been updated on 20/04/2018. Hence members and the public should expect it to be up-to-date. We critique various aspects of this as follows :-


Member Briefing Note

Comment from 20’s Plenty for us

2.2 In January 2013, the Department for Transport issued a new Circular on setting local speed limits to encourage local authorities to introduce more 20mph schemes. Area-wide 20 mph schemes have been introduced in Portsmouth and more recently Brighton and Hove and other towns and cities across the country are currently considering the introduction of area wide schemes.

The 2013 guidance included a priority for action to :-


“consider the introduction of more 20 mph limits and zones, over

time, in urban areas and built-up village streets that are primarily residential, to ensure greater safety for pedestrians and cyclists, using the criteria in Section 6.”


Why was this not important recommendation not mentioned?


We also note that as of today over 17m people (25% of UK’s population)  live in authorities that are committed to or have already implemented 20mph limits for most urban and village roads.


Why are only two authorities mentioned? Doesn’t this seriously misrepresent the implementation of 20mph limits?


2.3 In view of the increased pressure for the introduction of 20mph schemes, the challenge  for the County Council is how it prioritises    the requests for 20mph schemes against all of the other requests it receives for local transport improvements.


Surely the challenge is how it follows DfT guidance and its responsibilities for the built environment and safety of residents. The benefits of wide-area speed limit changes should be assessed, and only then should the budget be developed.

3.1 A reduction in vehicle speeds can reduce collisions and casualties but these benefits can only be realised where there is an existing crash history involving personal injury. An examination of the crash history in an area should therefore be a key factor in determining whether a scheme should be introduced.  

This is untrue. A large number of casualties for vulnerable road users are random and not clustered. Whilst we accept that some are clustered it is unreasonable to assume that a road without a casualty history will not benefit from a lower speed limit avoiding any future casualty. This statement therefore introduces the expectation that lower speed limits can only be set if roads have a history of casualties. Such an arbitrary condition (or key factor) therefore fails to take account of the needs of vulnerable road users as required in the DfT guidance para 32.

3.2       The Guidance suggests that the local traffic authority should work closely with the police and that in order to be successful 20 mph schemes should be self-enforcing, i.e. the existing conditions of the road together with any measures such as traffic calming, signing, or publicity should lead to a mean traffic speed compliant with the speed limit. The Guidance states that in order to achieve compliance there should be no expectation on the police to provide additional enforcement beyond their routine activity, unless this has been explicitly agreed.

This is misquoting the guidance which states that “Successful 20 mph zones and 20 mph speed limits are generally self-enforcing,”

There are many successful 20mph limits which may not be self-enforcing. Throughout the country roads with previous average speeds between 25 and 29mph have reduced by 7mph after implementing a 20mph limit.

4.1     20 mph zones introduced where speeds are above 24mph and use traffic calming measures at 100 metre intervals to slow vehicles down to speeds below the limit and ensure the zones is “self-enforcing”.

This fails to mention that DfT guidance now includes repeater signs and carriageway roundels as “traffic calming” devices. In addition, only one physical calming device is required in a 20mph zone. The TSRGD (signage regulations) now also leave the number and frequency of repeater signs and carriageway roundels to the “discretion of the local authority.”

4.2       A considerable amount of research has been undertaken on the impact of 20mph limit and zones. This has demonstrated that the implementation of a signed 20 mph limit typically only results in a 1 mph reduction in average speed.

This refers to the 1998 Mackay research which found this where nothing other than signage was used. Subsequent research in areas where wide area 20mph limits have been introduced with engagement shows a reduction in average speed of 2-3mph when averaged across both faster and slower roads. Note that the DfT guidance references a 6% reduction for every 1mph drop in average speed. Why has this not been referenced?

4.3 4.3            The County Council’s own experience through its rural speed limit review programme is consistent with the findings of national research in that significant reductions in speed have only been achieved in locations where physical features have been introduced as part of the speed limit reductions. The reductions in speeds where only signs and lines have been introduced have been much less.  

One has to ask how experience through rural speed limit review relates to urban speed limits. The note fails to mention that the cost of physically calmed interventions is some 50 times higher than signed only implementations. Hence the speed reduction per km per cost is substantially greater with un-calmed 20mph limits than with expensive, localised physically calmed zones.


When cost is fully taken into account 20mph limits are 7 times more cost effective at reducing speed than physically calmed zones. See http://www.20splenty.org/networkwide20

5.1 …As has been highlighted above, the introduction of a 20mph limit using signs alone is likely to have very limited speed reduction benefits. 

This is a misleading statement. Research shows reductions in speeds and casualties from introducing wide-area authority-wide 20mph limits. One report from Bristol showed an average reduction of 2.7mph and estimated casualty reductions of 4 fatalities, 11 serious injuries and 159 slight injuries per annum. See http://www.20splenty.org/bristol_20mph_analysis


This is consistent with other casualty reductions eg Warrington 27%, Edinburgh 25%, Bath 23%.


Also note a recent report from Calderdale Council showing a 30% reduction in casualties after introducing wide-area 20mph limits. See



5.1 …Although they can be relatively inexpensive to introduce, it is still difficult to justify the use of County Council funding to introduce them, except in a situation where it can be demonstrated that the scheme is likely to deliver road safety benefits or where there is the prospect of funding form an external source . By contrast, 20mph zones are more successful at delivering speed reduction but are far more expensive to introduce, which means they have to demonstrate that significant road safety benefits will  be achieved to justify the level of expenditure required .

This appears to be a “Catch 22” clause designed to suppress 20mph decisions. The council uses a flawed method for attributing road safety benefits by insisting on previous casualties and failing to take into account other community benefits such as active travel, emission reductions, etc. It then compares with schemes that may be effective but out of its own arbitrarily set funding budget.

5.3 Obviously each scheme request is assessed on its merits but typically requests for 20mph schemes do not tend to score highly unless there is a history of personal injury crashes where vehicle speed has been identified as being a contributory factor or there is the prospect of funding from an external source. 

With so many local authorities implementing successful wide-area 20mph limits one has to ask “what is the difference in East Sussex”. We have already identified that the method of assessing the value of limits is not in line with DfT guidance. Does the council realise how “out of touch” it is with communities requesting lower speed limits when they reply that “more casualties are required in your community before you can get lower speed limits”?

We would also question the use of “vehicle speed being a contributory factor”. Whilst speed may not have “caused” a collision it is inevitably implicated as the reason why a collision may not have been avoided or its casualty consequence mitigated.

6.However, there are insufficient resources to deliver comprehensive 20mph speed limits covering all residential areas or outside schools in the County.

The “resources” are arbitrarily being limited to manage expectations and set community against community in their requests for a liveable and safe environment. This need not be the case. Other urban and rural authorities have set 20mph limits for most residential streets.


We note that in neither of these documents are the needs of those with protected characteristics of age, disability or gender referenced.


Road danger and fear particularly effect the young and the old. Those with disability in movement, eyesight, mobility or spatial acuity are also disadvantaged by vehicle speed. Furthermore, it is mothers predominantly taking children to school who are most affected by their inability to trust speed limits to protect their children. Hence there is a gender imbalance in the risks on the roads for vulnerable road users.


30mph as a blanket speed limits for urban and village areas is now deemed as “unfit for purpose” by so many organisations, local authorities, national and international bodies including the DfT. I would therefore urge you to withdraw these two flawed documents pending a review of its speed limit policy with particular reference to its 20mph policy.


I would be pleased to engage with you to demonstrate how local authorities around the country are using wide-area 20mph implementations to benefit communities across road safety, active travel, public health, emission reduction and independent mobility.


I look forward to hearing from you.


Yours sincerely




Rod King MBE

Founder and Campaign Director

20’s Plenty for Us

+44 (0)7973 639781

[email protected]




20’s Plenty for Us

…making your place a better place to be


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